Physical Layer Authentication Mechanism Based on Interpolated Polynomial Method

Most of the existing physical layer challenge-response authentication methods assume that the attacker does not have access to the channel information of both legitimate parties. Their security relies on the privacy of the wireless channel strongly. However, in the actual communication environment, the above assumption is difficult to guarantee that if the attacking party obtains the legitimate channel information, it can directly crack the key based on the authentication response. To address these problems, this paper proposes a physical layer authentication mechanism based on the interpolated polynomial method using polynomial interpolation. First, the authentication parties extract the wireless channel characteristics and combine them with the shared key to obtain the joint key. Then both parties use the same key pair to construct their respective curve equations by Newton interpolation polynomial. Subsequently, the sender randomly selects the data not in the joint key to substitute into the equation to construct the authentication vector and send it to the authenticating party. Finally, the authenticating party sets the authentication threshold according to the requirements and calculates the matching result based on the data in the authentication vector for judgment. The simulation results show that the method has great security and authentication success rate.